Obturator assembly with selectively controllable fluid flow path

ABSTRACT

An obturator assembly includes an obturator positionable within a lumen of a device and movable within the lumen between a first position and a second position. The obturator includes a distal tip portion, wherein, with the obturator in the first position, the distal tip portion limits fluid communication through the lumen and, with the obturator in the second position, the distal tip portion provides fluid communication through the lumen.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/697,140, filed on Sep. 6, 2017, entitled OBTURATOR ASSEMBLY WITHSELECTIVELY CONTROLLABLE FLUID FLOW PATH, which is incorporated hereinin its entirety.

TECHNICAL FIELD

The present application relates generally to an obturator assembly. Morespecifically, the present application relates to an obturator assemblyhaving an obturator movably positioned within a catheter to selectivelycontrol a fluid flow through the catheter.

BACKGROUND

Commonly, conventional IV catheters are kept clear of clottingocclusions during their useful life by flushing the IV catheterperiodically with saline or another suitable cleansing fluid or liquid.During the flushing process, the fluid is moved through the catheter toflush out any thrombus-forming clotting material contained within thecatheter. Alternatively, some conventional IV catheters are kept clearof clotting occlusions by using an obturator to physically occupy aspace within the IV catheter lumen. The obturator method is notuniversally accepted because it requires the doctor or nurse to placethe obturator, which may have been recently exposed to an unsterileexternal environment, into the lumen of the catheter. This method mayincrease a risk of infection to the patient by positioning the obturatordirectly into the catheter such that the obturator may contact thepatient's blood stream. Further, when the IV catheter is used in atherapy setting, the obturator must be removed and discard, and areplacement obturator is required.

Many conventional obturators are positioned with in the catheter inorder to provide the occlusion prevention, and then removed to providefluid aspiration and/or infusion therapy. The used obturator should bediscarded after each use. This process must be repeated every time theIV catheter is accessed.

BRIEF SUMMARY OF SOME EXAMPLE EMBODIMENTS

In one aspect, an obturator assembly, includes a hub forming a centralpassage. A catheter has a distal end and an opposing proximal end. Thecatheter includes a small-bore connector at the proximal end coupled tothe hub. The catheter forms a lumen extending between the distal end andthe proximal end of the catheter. The lumen is in fluid communicationwith the central passage. An obturator is movably positioned within thelumen. The obturator is movable between a first position and a secondposition. The obturator includes a distal end having a tip portion. Withthe obturator in the first position, the distal end limits fluid flowthrough the lumen and, with the obturator in the second position, thedistal end provides a fluid flow path through the lumen.

In another aspect, an obturator is positionable within a lumen of adevice and movable within the lumen between a first position and asecond position. The obturator includes a distal tip portion. With theobturator in the first position, the distal tip portion limits fluidcommunication through the lumen of the device and, with the obturator inthe second position, the distal tip portion provides fluid communicationthrough the lumen of the device.

In yet another aspect, a method for selectably controlling a fluid flowin an obturator assembly is provided. The obturator assembly includes anobturator positioned within a lumen of a device, such as a catheter. Theobturator is movable within the lumen between a first position and asecond position. The method includes urging a proximal end of theobturator to move the obturator in a first direction within the lumen inone of a distal direction or a proximal direction with respect to adistal end of the catheter to provide a fluid flow path through thelumen.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective side view of an example obturator assembly in aclosed fluid flow path configuration according to example embodiments;

FIG. 2 is a partial perspective side view of the example obturatorassembly shown in FIG. 1;

FIG. 3 is a perspective side view of an example obturator assembly in anopen fluid flow path configuration according to example embodiments;

FIG. 4 is a partial perspective side view of the example obturatorassembly shown in FIG. 3;

FIG. 5 is a partial perspective side view of the example obturatorassembly shown in FIG. 3 with an alternative example obturator distalend;

FIG. 6 is a schematic side view of an example obturator assembly in alocked closed fluid flow path configuration according to exampleembodiments;

FIG. 7 is a schematic side view of an example obturator assembly in anunlocked open fluid flow path configuration according to exampleembodiments;

FIG. 8 is a schematic side view of an example obturator assembly in alocked open fluid flow path configuration according to exampleembodiments;

FIG. 9 is a partial perspective side view of an alternative exampleobturator assembly with an example obturator distal end;

FIG. 10 is a perspective side view of the example obturator assembly ofFIG. 9 in an open fluid flow path configuration according to exampleembodiments;

FIG. 11 is a partial perspective side view of an alternative exampleobturator assembly with an alternative example obturator distal end in afully open fluid flow path configuration according to exampleembodiments;

FIG. 12 is a perspective side view of the example obturator assembly ofFIG. 11 in a partially open fluid flow path configuration according toexample embodiments; and

FIG. 13 illustrates steps of an example method for operating an exampleobturator assembly according to example embodiments.

DETAILED DESCRIPTION

Various embodiments are described below with reference to the drawingsin which like elements generally are referred to by like numerals. Therelationship and functioning of the various elements of the embodimentsmay better be understood by reference to the following detaileddescription. However, embodiments are not limited to those illustratedin the drawings. It should be understood that the drawings are notnecessarily to scale, and in certain instances details may have beenomitted that are not necessary for an understanding of embodimentsdisclosed herein, such as—for example—conventional fabrication andassembly.

The invention is defined by the claims, may be embodied in manydifferent forms, and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey enabling disclosure to those skilled in the art. As used in thisspecification and the claims, the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Reference herein to any industry standards (e.g., ASTM, ANSI, IEEE, ISOstandards) is defined as complying with the currently publishedstandards as of the original filing date of this disclosure concerningthe units, measurements, and testing criteria communicated by thosestandards unless expressly otherwise defined herein. The terms“proximal” and “distal” are used herein in the common usage sense wherethey refer respectively to a handle/doctor-end of a device or relatedobject and a tool/patient-end of a device or related object. The terms“about,” “substantially,” “generally,” and other terms of degree, whenused with reference to any volume, dimension, proportion, or otherquantitative or qualitative value, are intended to communicate adefinite and identifiable value within the standard parameters thatwould be understood by one of skill in the art (equivalent to a medicaldevice engineer with experience in this field), and should beinterpreted to include at least any legal equivalents, minor butfunctionally-insignificant variants, standard manufacturing tolerances,and including at least mathematically significant figures (although notrequired to be as broad as the largest range thereof).

With reference to FIGS. 1-12, in example embodiments, an obturatorassembly includes a catheter having a distal end and an opposingproximal end. The catheter forms a lumen extending between the distalend and the proximal end of the catheter. An obturator is movablypositioned within the lumen between a first position and a secondposition. The obturator includes a distal tip portion. With theobturator in the first position, the distal tip portion prevents orlimits fluid communication and/or fluid flow through the lumen.Conversely, with the obturator in the second position, the distal tipportion provides fluid communication and/or fluid flow through thelumen. The obturator can be locked or secured in the first position orthe second position. The obturator is movable in at least one of adistal direction with respect to the distal end of the catheter or aproximal direction with respect to the distal end of the catheter fromthe first position to the second position. A hub forms a central passagethat is in fluid communication with the lumen with the hub coupled tothe catheter. A collar is operatively coupled to the hub and isconfigured in a locked configuration to prevent movement of theobturator within the lumen and in an unlocked configuration to allowmovement of the obturator within the lumen. In the locked configuration,the collar is configured to prevent movement of the obturator within thelumen with the obturator in the first position or the second position.The collar may be biased toward the locked configuration with theobturator in the first position or the second position. In exampleembodiments, at least a portion of the distal end of the obturator,e.g., at least a portion of a tip portion, has a symmetrical profilewith respect to a central axis of the obturator or an asymmetricalprofile with respect to the central axis.

The example embodiments described herein provide an obturator to preventcatheter occlusion that is not required to be removed prior to therapy.Rather, the multiple state obturator can be positioned in severalstates. For example, in a first or closed state, the obturator isconfigured to close or block a lumen of the catheter to preventocclusion and/or undesirable reverse blood flow, for example. In asecond state, the obturator can be moved within the lumen in a distaldirection and/or an opposite proximal direction. Further, the obturatormay have a reduced outer diameter in certain embodiments such that whenthe obturator is advanced, the obturator provides a fluid flow path orfluid opening to allow blood return or fluid infusion. As a result, theobturator does not have to be removed from the catheter lumen; thus,reducing a risk for infection and providing a reliable occlusionprevention mechanism. In particular embodiments, the obturator is madeof a suitable translucent material to act as a conduit for light-baseddisinfectant technology used in reducing bioburden in the intraluminalspace, for example. As described herein, the example multiple stateobturator is selectively controllable to prevent or allow fluid flowthrough the catheter without having to be removed. The obturatorassembly can remain installed for the duration of the therapy andprovide both an anti-occlusion mechanism and an infusion capability.

In example embodiments, an obturator assembly includes an obturatorpositionable within a lumen of a device, such as a catheter. Theobturator is movable between a first position and a second position. Theobturator has a distal tip portion, wherein, with the obturator in thefirst position, the distal tip portion limits fluid communicationthrough the lumen of the device and, with the obturator in the secondposition, the distal tip portion provides or allows fluid communicationthrough the lumen of the device. The obturator is configured to moveautomatically in a distal direction with respect to a device, e.g., thecatheter, toward a second or open position in response to a pressurecausing fluid to flow through the catheter lumen in the distal directionto allow the fluid to be expressed from the distal opening of the lumen.With the pressure decreased or removed, the obturator is configured tomove automatically toward a first or closed position. For example, asuitable pump operatively coupled to the obturator assembly may cycle topush fluid into the proximal end of the obturator assembly. In certainembodiments, the obturator includes a spring or another suitable biasingmember biasing the spring obturator toward the closed position. Theobturator is configured to automatically extend from the device, e.g.,the catheter, in a distal direction to allow the fluid to exit thecatheter lumen at the opposing distal end of the obturator assembly.Once the fluid has passed through the lumen and the fluid pressurewithin the lumen is decreased, e.g., removed, the obturator isconfigured to move automatically toward the first or closed position toseal the distal opening of the catheter. In particular embodiments, thepump may be configured to pump some fluid then reverse its peristalticcondition when used with a movable obturator to more fully re-seat theobturator in the sealed position.

Referring now to the figures, and initially to FIGS. 1-5, an exampleobturator assembly 10 includes a hub 12 forming a central passage 14 asshown in FIGS. 1 and 3. In example embodiments, central passage 14extends between a distal end 16 and an opposing proximal end 18 of hub12. As used herein, the terms “distal” and “distally” refer to alocation, a position, and/or a direction situated away from the hub,i.e., a point of origin or attachment, while the terms “proximal” and“proximally” refer to a location, a position and/or a direction situatedtoward the hub, i.e., the point of origin or attachment. Proximal end 18of hub 12 is configured to removably couple to any suitable medicaldevice or component, for example, standard medical tubing. As shown inFIGS. 1 and 3, for example, a suitable adapter 20 is formed on orcoupled to proximal end 18 to facilitate coupling hub 12 to the medicaldevice or tubing. In certain embodiments, hub 12 includes a small-boreconnector configured to couple hub 12 to a medical device or tubing. Themedical device or tubing may include a cooperating element 21 shown inFIG. 3, such as a small-bore connector lock, to facilitate coupling themedical device or tubing, for example, to hub 12.

A catheter 22 is operatively coupled to hub 12. In example embodiments,catheter 22 has a distal end 24 and an opposing proximal end 26.Catheter 22 may include a cannula extending from a distal end 24 towardan opposing proximal end 26 of catheter 22 in certain exampleembodiments. At proximal end 26, catheter 22 includes an adapter orbody, such as a small-bore connector 28 shown in FIGS. 1 and 3, forexample, to couple proximal end 26 of catheter 22 to distal end 16 ofhub 12. In certain embodiments, small-bore connector 28 is a small-boreconnector having a 6% tapered fluid connection per ISO 80369 for liquidsand gases in healthcare applications. In example embodiments, catheter22 forms or defines a lumen 30 extending between distal end 24 andproximal end 26 of catheter 22. In example embodiments shown in FIGS. 1and 3, lumen 30 is in fluid communication with central passage 14 toprovide a fluid flow path through obturator assembly 10. In exampleembodiments, each of lumen 30 and central passage 14 has a suitablediameter or a suitable cross-sectional dimension to facilitate fluidflow through obturator assembly 10. More specifically, in certainembodiments, fluid flows around a distal end of an obturator, such as anobturator 40 described below, movably positioned in lumen 30 and intoand through lumen 30 of catheter 22 with the obturator in an openposition or configuration.

Referring further to FIGS. 1-5, obturator assembly 10 includes anobturator 40 movably positioned within lumen 30. Obturator 40 is movablebetween a first position, such as a closed position shown in FIG. 1, anda second position, such as an open position as shown in FIG. 3.Obturator 40 has a distal end 42 and an opposing proximal end 44. Incertain embodiments, obturator 40 includes a tip portion 46 at distalend 42. Tip portion 46 transitions into a body 48 in a midsection ofobturator 40 and body 48 transitions into a base 50 at proximal end 44of obturator 40. In certain example embodiments as shown in FIGS. 6-8,body 48 and/or base 50 forms or defines a channel 52 providing fluidcommunication between lumen 30 and central passage 14. In exampleembodiments, with obturator 40 in the first position, distal end 42 and,in certain embodiments, tip portion 46, prevents or limits fluidcommunication and fluid flow through lumen 30. With obturator 40 in thesecond position, distal end 42 and, in certain embodiments, tip portion46, provides fluid communication such that fluid is able to flow throughlumen 30 into central passage 14 through channel 52. In particularembodiments, obturator 40 is made of a suitable translucent material toact as a conduit for light-based disinfectant technology used inreducing bioburden in the intraluminal space, for example.

In example embodiments, with obturator 40 in the first position, distalend 42, e.g., at least a portion of tip portion 46, is positioned withinlumen 30 to prevent fluid flow into lumen 30 and, with obturator 40 inthe second position, distal end 42, e.g., at least a portion of tipportion 46, extends from catheter 22 in a distal direction to allowfluid flow into lumen 30. Alternatively, in certain embodiments, withobturator 40 in the second position, distal end 42, e.g., at least aportion of tip portion 46, extends into lumen 30 of catheter 22 in aproximal direction to allow fluid flow into lumen 30. In exampleembodiments described herein, obturator 40 is movable from the firstposition to the second position in a distal direction with respect todistal end 24 of catheter 22, i.e., away from hub 12, to extend beyonddistal end 24 to provide a fluid flow path 54 as shown, for example, inFIGS. 4 and 5. Fluid flow path 54 provides fluid communication betweenlumen 30 and a lumen formed in a vessel, e.g., an artery or vein of apatient in which obturator assembly 10 is positioned. Referring to FIGS.1-5, in example embodiments, obturator 40 may be used independently ofthe other components of obturator assembly 10 and/or catheter 22 or maybe used with any suitable combination of one or more components ofobturator assembly 10 and/or catheter 22.

Referring again to FIGS. 6-8, in example embodiments, a fluid flow inobturator assembly 10, e.g., through at least lumen 30, is selectablycontrollable. For example, in certain example embodiments, obturator 40is urged at proximal end 44, e.g., by pushing at base 50 and/or hub 12,to move obturator 40 in a first direction within lumen 30 in the distaldirection with respect to distal end 24 of catheter 22 until distal end42, e.g., at least a portion of tip portion 46, extends distally fromlumen 30 of catheter 22 to provide fluid flow path 54 through lumen 30,as shown in FIGS. 7 and 8. Conversely, in these embodiments obturator 40is urged at proximal end 44, e.g., by pulling at base 50 and/or hub 12,to move obturator 40 in a second direction opposite the first directionwithin lumen 30 until distal end 42, e.g., at least a portion of tipportion 46 is at least partially positioned within lumen 30 to closefluid flow path 54, as shown in FIG. 6. In certain embodiments,obturator 40 can be moved automatically in the distal direction and theproximal direction using a pump or another suitable device. Inalternative example embodiments, obturator 40 is moveable in a proximaldirection with respect to distal end 24 of catheter 22, i.e., toward hub12, from the first position to the second position to extend into lumen30 a suitable distance to provide a fluid flow path (not shown in thefigures). The fluid flow path provides fluid communication between lumen30 and the lumen formed in the patient's vessel.

Obturator assembly 10 includes one or more seals, such as one or moresleeve seals, formed plastic seals, O-ring seals, or any suitable sealsknown to those having ordinary skill in the art. In certain embodiments,one or more O-ring seals 56 or other suitable seals or gaskets, arepositioned about an outer periphery 58 of proximal end 44 of obturator40 and contact an inner surface 60 of small-bore connector 28 atproximal end 26 of catheter 22. In certain embodiments, each O-ring seal56 is positioned within a respective annular slot 62 formed in innersurface 60 of small-bore connector 28 to properly maintain O-ring seal56 positioned about proximal end 44 of obturator 40 and betweenobturator 40 and catheter 22 to provide a fluid-tight seal withinobturator assembly 10.

Obturator 40 has a central axis 70, shown in FIGS. 2, 4, and 5,extending between distal end 42 and proximal end 44 of obturator 40. Inexample embodiments, at least a portion of distal end 42, e.g., at leasta portion of tip portion 46, has an asymmetrical profile, such as shownin FIGS. 2 and 4, with respect to central axis 70 or a symmetricalprofile, as shown in FIG. 5, with respect to central axis 70. Distal end42, e.g., at least a portion of tip portion 46, may have any suitableprofile that provides the desired fluid flow through fluid flow path 54.In certain conventional obturator assemblies, as a patient's blood isdrawn past the distal end of an obturator and into a lumen of thecooperating catheter, shear forces exerted on the red blood cells maydamage the red blood cells and may tear or rupture the red blood cellscausing destruction and disassociation of the red blood cells, sometimesreferred to as “hemolysis.” Unlike distal ends of conventionalobturators, distal end 42 and, particularly, at least a portion of tipportion 46, has a smooth, transitioning profile that facilitatesadministering or drawing fluids, e.g., blood, to or from the patientwhile preventing or limiting the damage and destruction of fluidmaterial and the occurrence of hemolysis, for example.

In example embodiments, an amount of fluid flow (i.e., a volume offluid) through fluid flow path 54 can be optimized by adjusting across-sectional area of an opening formed between an outer surface ofobturator 40 and an inner wall of catheter 22 forming lumen 30. Forexample, an outer diameter of obturator 40 and/or an inner diameter ofcatheter 22 at the distal end of catheter 22 may be adjusted to reducehemolysis and provide a desired blood sample during a blood drawapplication. For example, referring to FIG. 4, a relatively larger fluidflow path 54 may reduce or eliminate damage to the blood cells duringthe blood draw. Conversely, an equal amount of fluid flow through asmaller cross-sectional area, such as shown in FIG. 5, may providebetter infusion performance because the flow is equally divided aroundthe distal end of obturator 40.

As shown in FIGS. 1, 3, and 6-8, in example embodiments, obturatorassembly 10 includes a collar, such as a locking collar 72, operativelycoupled to hub 12. Locking collar 72 is configurable in a lockedconfiguration, such as shown in FIGS. 6 and 8, to prevent movement ofobturator 40 within lumen 30 and in an unlocked configuration, such asshown in FIG. 7, to allow movement of obturator 40 in the distaldirection and/or the opposite proximal direction within lumen 30. In thelocked configuration, locking collar 72 is configured to retainobturator 40 in a selected position, e.g., the first position or thesecond position. In FIG. 6, locking collar 72 is in the lockedconfiguration to retain obturator 40 in the first position, e.g., aclosed position preventing fluid flow through lumen 30, and preventobturator from moving from the first position, e.g., to the secondposition. In FIG. 7, locking collar 72 is in the unlocked configurationto allow obturator 40 to move with respect to catheter 22 in a distaldirection or an opposite proximal direction. As shown in FIG. 7, withlocking collar 72 in the unlocked configuration, obturator 40 can bemoved to the second position, e.g., an open position creating fluid flowpath 54 to allow fluid flow into lumen 30. In FIG. 8, with lockingcollar 72 in the locked configuration, obturator 40 is retained in thesecond position, e.g., the open position creating fluid flow path 54,and prevented from moving from the second position, e.g., to the firstposition.

In certain embodiments, locking collar 72 includes a tab 74 positionablewithin or configured to interfere with a depression 76 formed inobturator 40 with locking collar 72 in the locked configuration. Tab 74is actuatable to allow locking collar 72 to move between the lockedconfiguration and the unlocked configuration. For example, in exampleembodiments, tab 74 is depressed to allow locking collar 72 to move fromthe locked configuration to the unlocked configuration, which allowsobturator 40 to move between the first position and the second position.In certain example embodiments, locking collar 72 is biased toward thelocked configuration in one of the first position and the secondposition. More specifically, tab 74 may be biased, using a spring orother suitable biasing member (not shown in the figures), toward thelocked configuration in one of the first position and the secondposition.

Referring to FIGS. 9-12, in alternative example embodiments, one or morediffuser openings 80 are formed through catheter 22 to provide fluidcommunication between lumen 30 and a lumen formed in a vessel, e.g., anartery or vein of a patient in which obturator assembly 10 ispositioned. In these embodiments, at least a portion of distal end 42,e.g., at least a portion of tip portion 46, has an asymmetrical profile,such as shown in FIGS. 9 and 10, with respect to central axis 70 or asymmetrical profile, as shown in FIGS. 11 and 12, with respect tocentral axis 70. Distal end 42, e.g., at least a portion of tip portion46, has a suitable length along central axis 70 such that, withobturator 40 in the closed position, distal end 42 extends into lumen 30to seal the distal opening to lumen 30 as well as seal each diffuseropening 80 formed in catheter 22 to prevent or limit fluid flow throughlumen 30, as shown in FIG. 9. As shown in FIGS. 10 and 11, withobturator 40 in a fully open position, fluid is allowed to flow throughthe distal opening of lumen 30 as well as through one or more diffuseropenings 80. In a particular embodiment not shown in the figures,obturator 40 having an asymmetrical profile may seal one or morediffuser openings 80 preventing fluid flow through the sealed diffuseropenings 80 while allowing fluid flow through diffuser openings nearestthe asymmetrical aspect of obturator 40. Depending on the application ofobturator assembly 10, fluid is allowed to flow into (e.g., fluidinfusion) and/or out of (e.g., aspiration of fluid/blood drawn) lumen 30through the distal opening of lumen 30 and diffuser openings 80.However, as shown in FIG. 12, with obturator 40 in an intermediate orpartially open position, distal end 42, e.g., at least a portion of tipportion 46, extends into lumen 30 to seal the distal opening to lumen 30but provides fluid communication or allows fluid flow through diffuseropenings 80 formed in catheter 22. Again, depending on the applicationof obturator assembly 10, fluid is allowed to flow into and/or out oflumen 30 through diffuser openings 80 with the obturator in thepartially open position. In these alternative embodiments, obturator 40is configured to occlude diffuser holes 80 as well as the distal openingof lumen 30. This provides an added benefit of preventing occlusion atdistal end 24 of catheter 22 and in or around diffuser openings 80.Diffuser openings 80 also provide an added benefit for blood draws byproviding additional aspiration through diffuser openings 80 to furtherreduce hemolysis and may also be utilized for high-pressure injection.

FIG. 13 illustrates an example method 100 for selectively controlling afluid flow in an obturator assembly. In example embodiments, theobturator assembly includes a catheter forming a lumen and an obturatorpositioned within the lumen and movable between a first position and asecond position. The method includes moving 102 the obturator in a firstdirection within the lumen in one of a distal direction and a proximaldirection with respect to a distal end of the catheter to provide afluid flow path through the lumen. Moving 102 may include urging aproximal end of the obturator to move the obturator in a first directionwithin the lumen in a distal direction with respect to a distal end ofthe catheter, for example, to provide a fluid flow path through thelumen. As desired, the method also includes moving 104 the obturator ina second direction opposite the first direction within the lumen untilthe distal end, e.g., at least a portion of the tip portion, of theobturator is at least partially positioned within the lumen to close thefluid flow path. Moving 104 may include urging the proximal end of theobturator to move the obturator in a second direction opposite the firstdirection within the lumen until the distal end, e.g., at least aportion of the tip portion, of the obturator is at least partiallypositioned within the lumen to close the fluid flow path.

A collar, such as a locking collar, is operatively coupled to the hub ofthe obturator assembly. In example embodiments, the method includesconfiguring 106 the collar in a locked configuration to prevent movementof the obturator within the lumen or in an unlocked configuration toallow movement of the obturator in the distal direction and/or theopposite proximal direction within the lumen. In the lockedconfiguration, the collar is configured to retain the obturator in aselected position, e.g., the first position or the second position. Forexample, the collar can be positioned in the locked configuration toretain the obturator in the first position, e.g., a closed positionpreventing fluid flow through the lumen, and prevent the obturator frommoving from the first position, e.g., to the second position. The collarcan also be positioned in the locked configuration to retain theobturator in the second position, e.g., the open position creating afluid flow path, and prevent the obturator from moving from the secondposition, e.g., to the first position. The collar can also be positionedin the unlocked configuration to allow the obturator to move withrespect to the catheter in a distal direction or an opposite proximaldirection. With the collar in the unlocked configuration, the obturatorcan be moved between the first position and the second position, forexample. In certain example embodiments, the collar is biased toward thelocked configuration in one of the first position and the secondposition. More specifically, a tab of the collar may be biased, using aspring or other suitable biasing member, toward the locked configurationin one of the first position and the second position.

Those of skill in the art will appreciate that embodiments not expresslyillustrated herein may be practiced within the scope of the claims,including that features described herein for different embodiments maybe combined with each other and/or with currently-known orfuture-developed technologies while remaining within the scope of theclaims. Although specific terms are employed herein, they are used in ageneric and descriptive sense only and not for purposes of limitationunless specifically defined by context, usage, or other explicitdesignation. It is therefore intended that the foregoing detaileddescription be regarded as illustrative rather than limiting. And, itshould be understood that the following claims, including allequivalents, are intended to define the spirit and scope of thisinvention. Furthermore, the advantages described above are notnecessarily the only advantages of the invention, and it is notnecessarily expected that all of the described advantages will beachieved with every embodiment. In the event of any inconsistentdisclosure or definition from the present application conflicting withany document incorporated by reference, the disclosure or definitionherein shall be deemed to prevail.

We claim:
 1. A method to control fluid flow in an obturator assembly,the obturator assembly comprising an obturator movably positioned withina lumen of a catheter, the method comprising: moving the obturator froma proximal position to a distal position, wherein in response to theobturator being in the proximal position, a distal end of the obturatorlimits fluid flow through the lumen, wherein in response to theobturator being in the distal position, the distal end of the obturatorprovides a fluid flow path through the lumen of the catheter.
 2. Themethod of claim 1, further comprising moving the obturator from thedistal position to the proximal position.
 3. The method of claim 1,wherein the distal end of the obturator comprises a cylindrical portionand a reduced outer diameter portion proximate and proximal thecylindrical portion, wherein in response to the obturator being in thedistal position, the reduced outer diameter portion is aligned with adistal opening of the lumen of the catheter to provide the fluid flowpath through the lumen of the catheter.
 4. The method of claim 3,wherein the catheter further comprises a diffuser opening, wherein inresponse to the obturator being in the proximal position, thecylindrical portion occludes the diffuser opening and the distalopening.
 5. The method of claim 4, wherein in response to the obturatorbeing in the distal position, the reduced outer diameter portion is alsoaligned with the diffuser hole such that fluid is configured to flowthrough the diffuser hole.
 6. The method of claim 1, further comprisinglocking the obturator in the distal position.
 7. The method of claim 6,wherein the obturator assembly comprises a hub and a locking collaroperatively coupled to the hub, wherein the locking collar is configuredto lock the obturator in the distal position, wherein the locking collarcomprises a tab configured to selectively interfere with a depressionformed in the obturator in the distal position.
 8. The method of claim1, further comprising locking the obturator in the proximal position. 9.The method of claim 8, wherein the obturator assembly comprises a huband a locking collar operatively coupled to the hub, wherein the lockingcollar is configured to lock the obturator in the proximal position,wherein the locking collar comprises a tab configured to selectivelyinterfere with a depression formed in the obturator in the proximalposition.
 10. An obturator assembly, comprising: a catheter, comprisinga distal end and a proximal end, the catheter forming a lumen extendingbetween the distal end of the catheter and the proximal end of thecatheter; a hub forming a central passage; and an obturator extendingdistally from the hub, wherein the obturator is movable from a proximalposition to a distal position, wherein in response to the obturatorbeing in the proximal position, a distal end of the obturator limitsfluid flow through the lumen, wherein in response to the obturator beingin the distal position, the distal end of the obturator provides a fluidflow path through the lumen of the catheter.
 11. The obturator assemblyof claim 10, wherein the distal end of the obturator comprises acylindrical portion and a reduced outer diameter portion proximate andproximal the cylindrical portion, wherein in response to the obturatorbeing in the distal position, the reduced outer diameter portion isaligned with a distal opening of the lumen of the catheter to providethe fluid flow path through the lumen of the catheter.
 12. The obturatorassembly of claim 11, wherein the catheter further comprises a diffuseropening, wherein in response to the obturator being in the proximalposition, the cylindrical portion occludes the diffuser opening and thedistal opening.
 13. The obturator assembly of claim 12, wherein inresponse to the obturator being in the distal position, the reducedouter diameter portion is also aligned with the diffuser hole such thatfluid is configured to flow through the diffuser hole.
 14. The obturatorassembly of claim 10, wherein the obturator assembly comprises a hub anda locking collar operatively coupled to the hub, wherein the lockingcollar is configured to lock the obturator in the distal position,wherein the locking collar comprises a tab configured to selectivelyinterfere with a depression formed in the obturator in the distalposition.
 15. The obturator assembly of claim 10, wherein the obturatorassembly comprises a hub and a locking collar operatively coupled to thehub, wherein the locking collar is configured to lock the obturator inthe proximal position, wherein the locking collar comprises a tabconfigured to selectively interfere with a depression formed in theobturator in the proximal position.